The present disclosure relates in general to a replaceable fluid filter assembly and, in particular, to an anti-drip device for a replaceable fluid filter assembly that provides for the removal of the replaceable fluid filter assembly with a minimum of fluid spillage.
Replaceable fluid filter assemblies for industrial, commercial and consumer use are widely known throughout the industry. For example, modern refrigerators, which provide drinking water and produce ice, and beverage dispensing machines, such as coffee makers and soda dispensers, commonly use an internal filtration system having replaceable fluid filter assemblies for purifying the water.
Like most filtration systems and especially with respect to consumer appliances, the trend is toward using smaller, more compact, filter assemblies, frequent replacement of the filter media within the filtration system is required. Therefore, these filtration assemblies are typically equipped with replacement filter assemblies that can be disengaged from a system and replaced without requiring the removal of other components of the filter system. Unfortunately, such filter assemblies may not always be placed in the most accessible location or at the most desirable orientation conducive to reduce spillage during the replacement process.
Replacement filter assemblies typically include a filter cartridge in fluid communication with a manifold that is designed to be inserted into and removed from the source of fluid. Known filter cartridges include a filter element, such as a granular activated carbon filter element, located within a housing.
One representative example of a prior art filter assembly having a replaceable filter cartridge is disclosed in commonly assigned U.S. Pat. No. 6,632,355 to Fritze, the disclosure of which is herein incorporated by reference to the extent not inconsistent with the present disclosure. The Fritze patent discloses a replaceable water filter assembly having a cartridge and a manifold assembly fluidly coupled to the cartridge and to a water supply system. The cartridge, which includes a filter housing, a filter element, a filter dam, and an end cap, is a self contained, permanently assembled unit. The end cap of the cartridge unit includes a first flow path for supplying unfiltered water to the filter element and a second flow path for removing filtered water from the filter element. In the unfiltered water flow path, the end cap includes a plurality of small-diameter through bores. These small-diameter through bores are designed to prohibit water from spilling out of the filtered water flow path, when the water filter assembly is removed from the water supply system, by developing a vacuum within the cartridge. In addition, as part of the spill proof design of the system, spring valves are included in the unfiltered water flow path of the water manifold assembly. These spring valves are mechanically opened when the water filter assembly is coupled to the water supply system and mechanically closed upon detachment of the water filter assembly from the water supply system, thereby prohibiting the flow of unfiltered water from the water filter assembly during replacement.
One disadvantage of the known prior art is that the small-diameter through bores are integrally formed with the end cap, which, in turn, is integrally assembled into the cartridge. Since cartridges are not always associated with a manifold assembly located in locations where spillage is a concern, two distinct lines of cartridges must be produced: those to be used in low-spillage filter assemblies and those to be used in situations where spillage is not a concern. Another disadvantage of the prior art is the cost and complexity associated with having both mechanical spring valves and the small-diameter through bores to prohibit spillage from the replaceable filter assembly.
Thus, there is a need for an inexpensive, reliable replaceable fluid filter assembly that can be quickly and conveniently replaced. There is a particular need for a replaceable fluid filter assembly that can minimize spillage during cartridge replacement, while not significantly obstructing the flow or increasing the pressure drop. There is a further need for a replaceable fluid filter assembly that optionally can be supplied with an anti-drip feature after manufacture of the fluid filter cartridge.